1. Field of the Invention
This invention relates generally to communication systems, and, more particularly, to communication systems.
2. Description of the Related Art
Service providers typically provide numerous voice and/or data services to subscribers using one or more wired and/or communication systems. Exemplary services include cellular telephony, access to the Internet, gaming, broadcasting or multicasting of audio, video, and multimedia programming, and the like. Mobile subscriber units such as cell phones, personal data assistants, smart phones, pagers, text messaging devices, global positioning system (GPS) devices, network interface cards, notebook computers, and desktop computers may access the services provided by the communication systems over an air interface with a base station, base station router, or femtocell. The services are provided according to established and/or negotiated policies and the service providers typically charge the end-users for the services that are provided. For example, a cellular telephone service provider may charge an end-user for each minute of airtime that is used during voice communications. The billing rate may be determined based on a negotiated policy indicating the quality of service to be provided to the end user. For another example, end-users may be charged for each byte of data that is transmitted and/or received by the mobile unit operated by the end-user. Consequently, communication systems implement various charging and policy control architectures.
Conventional communication systems use a network of base stations to provide wireless connectivity to one or more mobile units. In some cases, the mobile units may initiate wireless communication with one or more base stations in the network, e.g., when the user of the mobile unit would like to initiate a voice or data call. Alternatively, the network may initiate the wireless communication link with the mobile unit. For example, in conventional hierarchical wireless communications, a server transmits voice and/or data destined for a target mobile unit to a central element such as such as a Radio Network Controller (RNC). The RNC may then transmit paging messages to the target mobile unit via one or more base stations. The target mobile unit may establish a wireless link to one or more of the base stations in response to receiving the page from the communication system. A radio resource management function within the RNC receives the voice and/or data and coordinates the radio and time resources used by the set of base stations to transmit the information to the target mobile unit. The radio resource management function can perform fine grain control to allocate and release resources for broadcast transmission over a set of base stations.
One alternative to the conventional hierarchical network architecture is a distributed architecture including a network of access points, such as base station routers, that implement distributed communication network functionality. For example, each base station router may combine RNC and/or PDSN functions in a single entity that manages radio links between one or more mobile units and an outside network, such as the Internet. Base station routers wholly encapsulate the cellular access technology and may proxy functionality that utilizes core network element support to equivalent IP functions. For example, IP anchoring in a UMTS base station router may be offered through a Mobile IP Home Agent (HA) and the GGSN anchoring functions that the base station router proxies by through equivalent Mobile IP signaling. Compared to hierarchical networks, distributed architectures have the potential to reduce the cost and/or complexity of deploying the network, as well as the cost and/or complexity of adding additional wireless access points, e.g. base station routers, to expand the coverage of an existing network. Distributed networks may also reduce (relative to hierarchical networks) the delays experienced by users because packet queuing delays at the RNC and PDSN of hierarchical networks may be reduced or removed.
At least in part because of the reduced cost and complexity of deploying a base station router, base station routers may be deployed in locations that are impractical for conventional base stations. For example, a base station router may be deployed in a residence or building to provide wireless connectivity to the occupants of the residents or the building. Base station routers deployed in a residence are typically referred to as home base station routers or femtocells because they are intended to provide wireless connectivity to a small area that encompasses a residence. However, the functionality in a home base station router is typically quite similar to the functionality implemented in a conventional base station router that is intended to provide wireless connectivity to a macro-cell that may cover an area of approximately a few square kilometers. One important difference between a home base station router and a conventional base station router is that home base station routers are designed to be plug-and-play devices that can be purchased off-the-shelf and easily installed by a lay person.
Femtocells are typically connected to the outside network using the user's existing home network infrastructure, such as a cable modem. Other entities may also use the home network infrastructure to access the outside network. For example, the home network may include one or more computers that are coupled to the cable modem via routers and/or wireless access points. In some cases, the cable modem may also be used to provide cable television services, video-on-demand services, telephone service, and the like. Consequently, a mobile unit must compete with these devices for resources when the mobile unit originates a call via the femtocell, receives a call via the femtocell, and/or hands off between the femtocell and the macro-cellular network. Conventional cable modem architectures, such as DOCSIS, only provide basic routing functions for the devices that are coupled to the cable modem. Conventional cable modems are not able to control the resources allocated to the femtocell according to established and/or negotiated policies associated with the mobile unit. This may lead to overloading of the DOCSIS network, which may degrade the quality of the connections associated with all of the applications connected to the cable modem.